1. Field of the Invention
The present invention relates to a medical image measurement device and method which measures features of a shape of an object of interest in a medical image, and a non-transitory computer-readable recording medium.
2. Description of the Related Art
In the related art, a predetermined feature quantity of an object of interest, such as a lesion, or a bone or an organ, included in a medical image, such as a radiation image, a magnetic resonance imaging (MRI) image, or an ultrasound image, is measured, and the growth of the lesion or the presence or absence of abnormality of the bone or the organ is confirmed based on the measurement result. For example, JP2014-54476A has suggested that bone mineral density is measured based on a radiation image obtained by photographing a bone. JP2013-39427A has suggested that the presence or absence of abnormality is determined by obtaining a change in the area of a small region of a lung using a radiation image obtained by photographing the lung. JP2013-111434A has suggested that the distance or the area between two points of a tumor or an area is measured using an ultrasound image.
For example, when confirming the growth of a lesion included in a medical image, it is considered to confirm the growth of the lesion by measuring the maximum diameter of the lesion included in a medical image photographed previously and the maximum diameter of the lesion included in a medical image photographed at this time and calculating a change in the length of the maximum diameter.
However, a lesion, such as a tumor, may grow while changing in shape from a state close to a circle to an ellipse. Specifically, as shown in FIG. 2, there is a case where the shape changes from a state close to a circle, like the lesion in the first medical image, to a state close to an ellipse extended in a predetermined direction, like the lesion in the second medical image.
Even in this case, as described above, when the maximum diameter (for example, a diameter specified by a point Pa1 and a point Pa2) of the lesion in the first medical image and the maximum diameter (for example, a diameter specified by a point Pb1 and a point Pb2) of the lesion in the second medical image are measured, and the amount of change is calculated, accurate growth of the tumor may not be measured. That is, the accurate growth may not be measured without consideration of a change over time of the tumor or the like. Here, although description will be provided regarding an example where a lesion is enlarged, the same applies to a case where a lesion is reduced.